1. Field of the Invention
The present invention generally relates to a ground fault circuit interrupter (GFCI) unit and, more particularly, is concerned with a button well compression seal assembly employed in the GFCI unit.
2. Description of the Prior Art
As is well-known, a GFCI unit is a device for protecting an electrical circuit from the hazards of ground fault currents, as distinguished from other types of faults such as short circuits and other overcurrent abnormalities. A ground fault is one which occurs, in a circuit having a neutral conductor grounded at its source, when contact is made with an electrified conductor in the circuit through a person or a conductive article in contact with the ground. This results in a ground fault current flowing back to the grounded source partially or wholly through a ground path.
One GFCI unit commercially-available from Harvey Hubbell Incorporated of Bridgeport, Connecticut, USA, includes a housing enclosing an arrangement of electronic and electro-mechanical components which interconnect corresponding live, neutral and ground conductors of a pair of three-wire electrical power cords. The conductors of one of the power cords are terminated by a male plug, while the conductors of the other power cord are terminated by a female plug. The electro-mechanical components of the GFCI unit include test and reset buttons which are accessible through openings defined in the front side of the housing.
The housing of the GFCI unit must be hermetically sealed to keep out moisture which would disrupt the proper functioning of the electronic and electro-mechanical components contained therein. The housing is comprised of a front cover and rear base which at their rims are adhesively sealed to one another about most of their peripheries and to strain relief connectors on the power cords at their opposite ends. However, a potential source of moisture infiltration exists through the openings in the front cover which provide access to the test and rest buttons.
Consequently, a need exists for some means to provide hermetic seals between the housing openings and the test and reset buttons which will prevent moisture from entering the housing but at the same time not interfere with the proper functioning of the test and reset buttons.